Wireless communication systems are rapidly growing in usage. Further, wireless communication technology has evolved from voice-only communications to also include the transmission of data, such as Internet and multimedia content. A user equipment (“UE”) may be configured to establish a connection with different types of networks through the use of wireless communications protocols. Accordingly, based upon the capabilities of the hardware and software of the UE, the UE may connect with these different types of networks. For instance, the network may be a Universal Mobile Telecommunication System (“UMTS”) or Long Term Evolution (“LTE”) network for data connectivity, or the network may be a Global System for Mobile Communications (“GSM”) or Code Division Multiple Access (“CDMA”) network for voice connectivity.
LTE, commonly referred to as “4G LTE,” is a standard for wireless communication of high-speed data for mobile phones and data terminals. The LTE standard has been developed by the 3rd Generation Partnership Project (“3GPP”) and is described as a natural upgrade path for carriers using prior generation networks or “legacy” protocols or 2G/3G networks, such as GSM/UMTS protocols and CDMA 2000 1× (e.g., 1×RTT or simply “1×”) wireless communication protocols. In addition, standards are being developed for new 5G networks. Each of these different types of networks and protocols may be termed radio access technologies (“RATs”).
In addition, network operators for these various RATS establish and provide a public land mobile network (“PLMN”), as defined in telecommunications regulations, for the purpose of providing mobile telecommunications services to the public. Accordingly, each network operator offering mobile services has its own PLMN that interconnects with other PLMNs as well as the public switched telephone network (“PSTN”). Furthermore, a PLMN may communicate with Internet Service Providers for internet access and data communications.
An exemplary PLMN is identified by a PLMN-ID based on a combination of a Mobile Country Code (“MCC”) and a Mobile Network Code (“MNC”). In addition, an equivalent home PLMN (“EHPLMN”) list allows for the home PLMN (“HPLMN”) operator to identify alternative Network IDs as a HPLMN. For instance, when selecting a network that is not the HPLMN, the highest priority EHPLMN available shall be selected. The EHPLMN list is typically provisioned by the network operator and stored in a universal subscriber identity module (“USIM”). In addition to the EHPLMN list, the UE may also utilize a User PLMN (“UPLMN”) list, wherein the end user may set the PLMN and the RAT, and an Operator PLMN (“OPLMN”) list, wherein the operator may set the RAT. Accordingly, the entries in either the UPLMN list or the OPLMN list are PLMN and RAT combinations. Thus, a user or operator may specify the PLMN in the OPLMN/UPLMN lists.
In the current 3GPP specification, PLMNs in EHPLMN lists, UPLMN lists and OPLMN lists include absolute priorities. Specifically, the first PLMN on the list has the highest priority, the last PLMN on the list has the lowest priority, and no PLMN has the same priority as another PLMN. However, this absolute priority approach has limitations for both end users and operators.